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From:   Jun Li <lijun.kernel@gmail.com>
Date:   Wed, 23 Sep 2020 18:33:26 +0800
Message-ID: <CAKgpwJUikcsbYz6Uy-iQsXgpDpBzJDpxTretYSfubfEJ7X5yWg@mail.gmail.com>
Subject: Re: [RESEND PATCH v2 1/6] dt-bindings: connector: add power-opmode
 optional property to usb-connector
To:     Amelie DELAUNAY <amelie.delaunay@st.com>
Cc:     Rob Herring <robh+dt@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        Russell King <linux@armlinux.org.uk>,
        Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>, lkml <linux-kernel@vger.kernel.org>,
        Linux USB List <linux-usb@vger.kernel.org>,
        linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org,
        Fabrice Gasnier <fabrice.gasnier@st.com>
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Amelie DELAUNAY <amelie.delaunay@st.com> =E4=BA=8E2020=E5=B9=B49=E6=9C=8823=
=E6=97=A5=E5=91=A8=E4=B8=89 =E4=B8=8B=E5=8D=885:31=E5=86=99=E9=81=93=EF=BC=
=9A
>
>
>
> On 9/23/20 11:08 AM, Jun Li wrote:
> > Amelie Delaunay <amelie.delaunay@st.com> =E4=BA=8E2020=E5=B9=B49=E6=9C=
=882=E6=97=A5=E5=91=A8=E4=B8=89 =E4=B8=8B=E5=8D=884:01=E5=86=99=E9=81=93=EF=
=BC=9A
> >>
> >> Power operation mode may depends on hardware design, so, add the optio=
nal
> >> property power-opmode for usb-c connector to select the power operatio=
n
> >> mode capability.
> >>
> >> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
> >> ---
> >> Changes in v2:
> >> - Add description for possible operation current values
> >> ---
> >>   .../bindings/connector/usb-connector.yaml     | 20 +++++++++++++++++=
++
> >>   1 file changed, 20 insertions(+)
> >>
> >> diff --git a/Documentation/devicetree/bindings/connector/usb-connector=
.yaml b/Documentation/devicetree/bindings/connector/usb-connector.yaml
> >> index 9bd52e63c935..2fd85b9a7e1a 100644
> >> --- a/Documentation/devicetree/bindings/connector/usb-connector.yaml
> >> +++ b/Documentation/devicetree/bindings/connector/usb-connector.yaml
> >> @@ -88,6 +88,26 @@ properties:
> >>         - device
> >>         - dual
> >>
> >> +  power-opmode:
> >> +    description: Determines the power operation mode that the Type C =
connector
> >> +      will support and will advertise through CC pins.
> >> +      - "default" corresponds to default USB voltage and current defi=
ned by the
> >> +        USB 2.0 and USB 3.2 specifications, 5V 500mA for USB 2.0 port=
s and
> >> +        5V 900mA or 1500mA for USB 3.2 ports in single-lane or dual-l=
ane
> >> +        operation respectively.
> >> +      - "1.5A" and "3.0A", 5V 1.5A and 5V 3.0A respectively, as defin=
ed in USB
> >> +        Type-C Cable and Connector specification, when Power Delivery=
 is not
> >> +        supported.
> >> +      - "usb_power_delivery" when Power Delivery is supported, as def=
ined in
> >> +        USB Power Delivery specification.
> >
> > Why need "usb_power_delivery"? isn't this information can be implied by
> > existing properties like if "source-pdos" is present?
> >
>
> power-opmode is an optional property.
> usb_power_delivery, as 3.0A, 1.5A or default here, only reflect the
> possible power operation mode you can set and that are understood by
> typec class:
> static const char * const typec_pwr_opmodes[] =3D {
>         [TYPEC_PWR_MODE_USB]    =3D "default",
>         [TYPEC_PWR_MODE_1_5A]   =3D "1.5A",
>         [TYPEC_PWR_MODE_3_0A]   =3D "3.0A",
>         [TYPEC_PWR_MODE_PD]     =3D "usb_power_delivery",
> };
>
> But I guess that a Type-C controller with usb power delivery support
> won't use power-opmode property but rather source/sink-pdos.
>
> power-opmode shows what will be advertised through CC pins. I can remove
> usb_power_delivery from the possible values, but what about the user who
> will add power-opmode property to configure his Type-C controller with
> USB power delivery support (sink and/or source by the way) ?

With power delivery support, this information should be abstracted from
source-pdos.

> Should I restrict the use of power-opmode to non-USB power delivery
> Type-C controllers ?

I think Yes. only need it for non-PD(power source/DRP).

Li Jun
> Please advise.
>
> Regards,
> Amelie
>
>
> > Li Jun
> >> +    allOf:
> >> +      - $ref: /schemas/types.yaml#definitions/string
> >> +    enum:
> >> +      - default
> >> +      - 1.5A
> >> +      - 3.0A
> >> +      - usb_power_delivery
> >> +
> >>     # The following are optional properties for "usb-c-connector" with=
 power
> >>     # delivery support.
> >>     source-pdos:
> >> --
> >> 2.17.1
> >>